Bows and crossbows use at least one bowstring or cable to hold tension in their limbs and to shoot arrows and bolts. A traditional bow, recurve bow, or crossbow may have a single bowstring connecting the limbs. Compound bows and crossbows typically have a long bowstring that wraps around the end cams and is used to shoot the arrow. A control buss cable (CBC) connects the bottom cam to the top cam (or vice versa), and a yoked buss cable (YBC) connects the top axle to the bottom cam (or vice versa).
Materials used for strings in bows have evolved over time from sinew and horsehair to steel cabling, to current thermoplastic fibers and other modern materials bundled together. With almost all of these materials, the string is formed when multiple fibers are twisted or otherwise connected to each other. Each strand typically has similar material construction and length. The strands are then twisted together and entwined into bundles or rope-like cords having the length and shape needed for the strings. Some portions may also be “served” or covered with an external cord and/or coating in high-wear areas with serving material that wraps generally circumferentially around the diameter of the entwined strands.
Constructing a bowstring in this manner provides a bowstring with strand material that has high elastic modulus, high tensile break strength, high efficiency (often due to the strand material having low density), and the ability to separate the bundle of fibers into two side-by-side halves in a manner enabling the archer to place a peep sight into the string. The entwined string is also relatively easy to make since the string generally consists of one continuous strand of material (or in some cases two strands having the same material but different color) which is wrapped multiple times in a loop configuration without having to be cut along its length.
When attached to a bow or crossbow, cables and bowstrings are adjusted and tuned to exact specifications in order to maximize efficiency and reduce vibrations, noise, and other potentially negative effects. However, constantly high tensile loads and repeated load cycles tend to elongate the strings over time, thereby decreasing the number of “twists per inch” of the entwined strands along the length of the strings. Environmental conditions (e.g., temperature and humidity) can also elongate or shrink the strings. As a result, accessories such as peep sights or cable splitters that are positioned between bundles of strands of the string tend to rotate relative to the bow over time. The original positioning of these types of accessories is based on a certain length and twist rate of the string, so as those factors change over time, the directional orientation of the accessories change as well, leading to problems such as partially turned peep sights or twisted YBC or CBC ends that connect to cams. The accuracy and efficiency of the bow or crossbow can thereby deteriorate over time. For these and other reasons, archers and other sportsmen are constantly seeking improvements to bowstrings and cables used in archery equipment.